French prosecutors have widened their investigation into corruption in athletics to include the bidding and voting processes for the hosting of the 2016 and 2020 Olympics.

The former president of world governing body the IAAF, Lamine Diack, is already being investigated by French authorities.

He was arrested last year on corruption and money laundering charges. Confirming the investigation was being widened, an official from the prosecutor’s office said: “We are looking at these elements, but at this stage it is a question of verification.

Nothing has been proved.” The International Olympic Committee said it wants to be a party to the French investigations. Tokyo, which will host the 2020 Olympics, defended the voting process when it came under scrutiny in January.

And Rio 2016 organizers said that the city “won the right to host the Games because it had the best project”, foreign media reports.